“HERA and the LHC” Workshop 2006-2008 WG3 – Heavy Quarks Summary

HERA-LHC Workshop, CERN, 30.05.2008 WG3 - Heavy Quarks 1

“HERA and the LHC” Workshop 2006-2008

WG3 – Heavy Quarks Summary

WG3 Conveners:M.Cacciari, A.Dainese, A.Geiser, H.Spiesberger


HERA resultson charm and beauty


Beauty in photoproduction

HERA/LHC 2005:


Beauty in photoproduction

S.Boutle

reasonableagreementwith NLO QCDpredictions

theory appropriate for LHC many HERA II results still to come

2008:


Charm production at HERA A. Jung

full HERA II statistics2008:


Azimuthal correlations & MC@NLO

direct resolved enriched enriched

NLO

norm. OKshape X

MC@NLO for HERAnow almost ready!

needNNLOor

NLO+PS(MC@NLO)

data:

charm+ dijet

(jj)T.Toll

2005:

2008:



Heavy quarks in F2


beauty contribution to F2

HERA LHC, e.g. H, Z

Q2 >> mb2

2005:


P. Roloff

2008:

~10 x more to come

beauty contribution to F2


Charm contribution to F2

combination efforts ongoing

understand mass effectsfrom beauty

-> improved theory

-> validate gluon PDF´s for LHC

2008:


Heavy quark-related news in M(R)ST(W) PDF sets

New prescription – ACOT() – for coefficients functions at the thresholds New preferred values for the charm (1.4 GeV) and bottom (4.75 GeV) masses, obtained from detailed 2 analyses Study of intrinsic heavy quarks

up to 0.3% intrinsic charm allowed by EMC data on F2

c

R. Thorne


R. Thorne


R. Thorne


Towards 3-loop (s3) F2

c

I. Bierenbaum


I. BierenbaumTowards 3-loop (s

3) F2c


A look to the near future:perspectives at LHC


LHC: heavy quarks factory

Cross sections: NLO (MNR)

mc=1.2 GeV, F=R=2mc; mb=4.75 GeV, F=R=mb

Yields: assuming ppinel = 70 (40) mb

at 14 (0.9) TeV

LHC startup at 10 TeV:cross sections smaller by 20% w.r.t. 14 TeV


Updated benchmark cross sections

from HERA-LHC 04/05 Proceedings

Update for b at 14 TeV (MC@NLO by R. Guernane):

charm, pp 14 TeV

NEW


H. Spiesberger

accessible with HQ at HERA

need to measure c and b down to low pt!!



Acceptance for open heavy flavor at LHC

ALICE (c/b)

ATLAS/CMS (b) LHCb

(b)

-2 0 2 4 61

10

100

1 year pp 14 TeV @ nominal lumin.

pT o

f Q

-had

ron

[G

eV]

of Q-hadron

ALICE (b) (c)

important: complementarity of the 4 experiments

H1/ZEUS


CMS & ATLAS(A.Starodumov, V.Andreev, R.Wolf) (M.zur Nedden, J.Ginzburg, E.Lytken)

Muon detectionCalorimetrySilicon trackersAbout (only) 5% of trigger bandwidth for B Physics


CMS & ATLAS: B programmes

CP violation (e.g. B→J/ψ(X), B→)Bs oscillations (e.g. Bs→Dsπ, Bs→Dsa1)Rare decays (e.g. B→(X), B→K*γ)Inclusive cross section measurement

CMS

ATLAS


CMS & ATLAS: b production measurement

up to > 1 TeV/c!

CMS: b-jet tagging

bcJp

MLt

T

Jxy

)/(/

ATLAS: displaced J/ from B

+ several exlcusive channels

Channel N (100 pb-1)

B+ J/ K+ 17000

B0 J/ K0* 8700

Bs J/ 900

b J/ 260


LHC vs HERA: one heavy quark more (top!)

(> 2104 GeV2)


Theoretical developments in top production at LHC



LHCb(K.Harrison)

dedicated to B PhysicsCP violation

rare decays

B spectroscopy

many complementary channels

example: measurement of b cross sectioninclusive displaced muons

inclusive displaced J/ & D’s

exclusive B mesons

e.g. B+J/K+


ALICE (C.Bombonati, D.Stocco,R.Guernane,G.Bruno)

down to (almost) 0 pT!

Pb-Pb 5.5 TeVpp 14 TeVp-Pb 8.8 TeV

D0 K + B e + X

Charm Beauty


tot tot J/y bkgJ/y from B

CDF

pT>0

This measurement will be performed by all 4 LHC experiments

COMPARE

2<pT<3 Gev3<pT<5 GevpT>5 Gev

ALICE

displaced J/e-e+ALICE


Quarkonia production at LHCAmong first measurements + theoretical interest: What is the production mechanism?

The Color Octet Mechanism agrees well with measured shape from Tevatron Polarization measurements:CDF sees no sign of pol. for J/, and DØ (1S) measurements not consistent with predictions.

More data with high-pT needed!

Coloroctet

Color singlet

Tevatron data

NRQCD

(1s)

J/

kT factorization model

E. Lytken (ATLAS Collaboration) HERA-LHC workshop May 2008 9

Quarkonia Among first measurements

+ theoretical interest: What is the production

mechanism?

The Color Octet Mechanism agrees well with measured shape from TevatronPolarization measurements:CDF sees no sign of pol. for J/, and DØ (1S) measurements not consistent with predictions.

More data with high-pT needed!

Coloroctet

Color singlet

Tevatron data

NRQCD

(1s)

J/

kT factorizationmodel


E. Lytken (ATLAS Collaboration) HERA-LHC workshop May 2008 15

J/* = ATLAS~10 pb-1

* *** *

0.8 fb-1

Quarkonia PolarizationMainly based on muon triggers but in initial period will also have electron channels for comparisonAlready with 10 pb-1: measure J/ pol. to same precision as TeV with 1.3 fb-1 - but with interesting high pT data!Same precision for polarization studies can be reached after ~100 pb-1

Crude superimpose of ATLAS stat uncertainties with 10 pb-1 assuming =0 :

NRQCD

*

*

*

*

* = ATLAS~10 pb-1

*

measurement will be performedby all 4 experiments


Forward J/ production at ALICE

gg contribution dominant

normalized to 1

=> study shape only

sensitive to gluon PDFdown to x=10-6


Summary and ConclusionsHeavy Flavour production in ep and pp collisions is good testing ground for perturbative QCD

charm production: reasonably described, no clear preference

between "massive" NLO and "massless" NLL calculations.

NNLO or NLO+PS needed for some regions of phase space

MC@NLO now available for HERA; should be used for LHC

beauty production: reasonable description at high pTb -> OK for LHC

results seen at this workshop show agreement down to low pTb

Charm and beauty production at low pt at LHC: small-x effects?

saturation? to be measured by LHC experiments

DIS (F2): both charm and beauty well described first measurement of F2

bb understand mass effects, then extract b and gluon for LHC

J/production: LHC experiments have potential to clarify theory interpretation of picture emerging from Tevatron and HERA data


Thanks to:

WG3 speakersWG3 participants

the organizers

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“HERA and the LHC” Workshop 2006-2008 WG3 – Heavy Quarks Summary

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